Patents by Inventor Vikram Chandrasekhar

Vikram Chandrasekhar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20130215835
    Abstract: This invention is a technique for coordinate multi-point wireless transmission between plural base stations and user equipment. At least one base station transmits via a Physical Downlink Shared CHannel (PDSCH). The user equipment does not know the identity of the plural base stations. This could include joint transmission by simultaneous data transmission from multiple base stations. This could include dynamic point selection by data transmission from one base station at a time and changing the transmitting point (TP) from one subframe to another subframe. This could include coordinated scheduling/beamforming (CS/CB) where data is transmitted to the user equipment from one base station at a time and the base stations communicate to coordinate user scheduling and beamforming. The transmission point (TP) could vary over Resource Block (RB) pairs within a subframe while never transmitting from more than one base station. The transmission point (TP) could change in a semi-static fashion.
    Type: Application
    Filed: August 15, 2012
    Publication date: August 22, 2013
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Runhua Chen, Eko N. Onggosanusi, Anthony Ekpenyong, Vikram Chandrasekhar
  • Patent number: 8514738
    Abstract: The primary serving base station transmits PDSCH with zero energy on the inter-cell CRS resource element location. This is called mute PDSCH. Within the first Physical Resource Block (PRB 0), the RE positions in the frequency domain are indexed between 0 and 11. The muted PDSCH RE positions per antenna port are computed using the cell IDs of all CoMP cells other than the cell ID i. The invention defines the Orthogonal Frequency Division Multiplexing (OFDM) symbols in which muting occurs.
    Type: Grant
    Filed: March 30, 2011
    Date of Patent: August 20, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Vikram Chandrasekhar, Eko N. Onggosanusi, Anthony Ekpenyong, Runhua Chen
  • Publication number: 20130077574
    Abstract: This patent application considers the configuration aperiodic sounding reference signal parameters by radio resource control signaling and the triggering of aperiodic SRS transmission by detection of a positive trigger in downlink control information. Transmission timing rules are also proposed to determine the valid subframes for aperiodic SRS transmission.
    Type: Application
    Filed: September 22, 2011
    Publication date: March 28, 2013
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Anthony Ekpenyong, Vikram Chandrasekhar, Pierre Bertrand
  • Publication number: 20130021973
    Abstract: In an embodiment, a wireless communication system (100, FIG. 1) includes one or more nodes (102-108) and one or more user equipments (UE) (110). A node may apply (502, FIG. 5) a cell-specific spreading code to a cell identifier, which indicates an identity of a cell (113, FIG. 1) serviced by the node. The node may insert (504, FIG. 5), into a frame (200, FIG. 2), at least one synchronization channel symbol, which corresponds to the spread cell identifier, and the node may transmit (506, FIG. 5) the frame over an air interface. A UE may receive (702, FIG. 7) a frame from the air interface. The UE may despread (708) the spread cell identifier, and acquire (712) a cell identifier corresponding to a particular cell.
    Type: Application
    Filed: July 23, 2012
    Publication date: January 24, 2013
    Inventors: Ahsan U. Aziz, Vikram Chandrasekhar, James Wesley McCoy
  • Publication number: 20120287799
    Abstract: A method of Coordinated Multipoint (CoMP) communication between a base station has a plurality of points with at least one user equipment (UE). At least one UE receives at least one transmission from the base station having the plurality of points. This UE measures downlink channel state information for each of the plurality of points including a rank indicator (RI), a precoding matrix indicator (PMI) and a channel quality indicator (CQI). This UE transmits the downlink channel station information in an uplink feedback channel to the base station.
    Type: Application
    Filed: May 9, 2012
    Publication date: November 15, 2012
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Runhua Chen, Vikram Chandrasekhar, Eko Onggosanusi
  • Publication number: 20120275400
    Abstract: A wireless transmission system included at least one user equipment and a base station. The base station is operable to form a downlink control information block, modulate the downlink control information, precode the modulated downlink control information, and transmit the precoded, modulated downlink control information on at least one demodulation reference signal antenna port to the at least one user equipment. The precoded, modulated downlink control information is mapped to a set of N1 physical resource block pairs in a subframe from an orthogonal frequency division multiplexing symbol T1 to and orthogonal frequency division multiplexing symbol T2.
    Type: Application
    Filed: April 27, 2012
    Publication date: November 1, 2012
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Runhua Chen, Eko N. Onggosanusi, Vikram Chandrasekhar, Anthony Ekpenyong
  • Publication number: 20120269278
    Abstract: A base station selects a subset of at least one geographically separated antennas for each of the plurality of user equipments. The base station forms at least layer of data stream including modulated symbols, precodes the data stream via multiplication with the NT-by-N precoding matrix where N is the number of said layers and NT is the number of transmit antenna elements and transmits the precoded layers of data stream to the user equipment via the selected geographically separated antennas. The base station signals the subset of the plurality of geographically separated antennas via higher layer Radio Resource Control or via a down link grant mechanism. The base station optionally does not signal the subset of the plurality of geographically separated antennas to the corresponding mobile user equipment.
    Type: Application
    Filed: April 20, 2012
    Publication date: October 25, 2012
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Eko Onggosanusi, Vikram Chandrasekhar, Runhua Chen
  • Publication number: 20120264441
    Abstract: This invention includes signaling schemes for communicating the PDSCH muting configuration from the eNodeB to its UEs so that they can measure inter-cell CSI if configured. The base station transmits to each served user equipment a number signal indicating a number of allowed muting configurations, parameters for each allowed muting configuration and an enable/disable signal. Each served user equipment mutes or does not mute a physical downlink shared channel according to one of the allowed muting configurations and the state of a corresponding bit of the enable/disable signal.
    Type: Application
    Filed: July 18, 2011
    Publication date: October 18, 2012
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Vikram Chandrasekhar, Runhua Chen
  • Publication number: 20120243500
    Abstract: This invention is a method of wireless communication using candidate multi-cell CSI-RS time-frequency patterns in the invention. This invention avoids collision with antenna ports 0, 1, 2 and 3 used for transmitting cell-specific reference signals and port 5 used for transmitting demodulation reference signals. This invention satisfies the nested property requirement. This invention avoids collision with DM-RS signal for extended cyclic prefix transmission as long as DMRS Rank is less than or equal to 2. For ranks greater than 2, this invention produces patterns that may collide with Rel. 10 DM-RS for extended CP. The invention includes alternative patterns obtained by relabeling and/or reshuffling the CSI-RS antenna port numbers while preserving identical time-frequency resources assigned to CSI-RS in the time-frequency grid.
    Type: Application
    Filed: June 1, 2011
    Publication date: September 27, 2012
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Vikram Chandrasekhar, Eko N. Onggosanusi, Runhua Chen
  • Publication number: 20120201154
    Abstract: This invention sets conditions for user equipment responses to channel state indicator request in channel station information that may conflict.
    Type: Application
    Filed: January 11, 2012
    Publication date: August 9, 2012
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Vikram Chandrasekhar, Runhua Chen, Anthony Ekpenyong
  • Patent number: 8228887
    Abstract: In an embodiment, a wireless communication system (100, FIG. 1) includes one or more nodes (102-108) and one or more user equipments (UE) (110). A node may apply (502, FIG. 5) a cell-specific spreading code to a cell identifier, which indicates an identity of a cell (113, FIG. 1) serviced by the node. The node may insert (504, FIG. 5), into a frame (200, FIG. 2), at least one synchronization channel symbol, which corresponds to the spread cell identifier, and the node may transmit (506, FIG. 5) the frame over an air interface. A UE may receive (702, FIG. 7) a frame from the air interface. The UE may despread (708) the spread cell identifier, and acquire (712) a cell identifier corresponding to a particular cell.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: July 24, 2012
    Assignee: Apple Inc.
    Inventors: Ahsan U. Aziz, Vikram Chandrasekhar, James Wesley McCoy
  • Publication number: 20120063321
    Abstract: This invention mitigates interference in wireless telephony in heterogeneous networks having a macro base station and a low power base station. This invention attempts to avoid cross carrier scheduling on an anchor carrier and a non-anchor carrier. If cross carrier scheduling is unavoidable, then this invention attempts: (1) semi-statically signalling a CFI value on a cross-scheduled component carrier; (2) semi-statically signalling a channel quality information (CSI) value on a cross-scheduled component carrier setting a Physical Hybrid ARQ Indicator CHannel (PHICH) value to be maximum; or (3) semi-statically signalling a channel quality information (CSI) value on a cross-scheduled component carrier using Physical Control Format Indicator CHannel (PCFICH) power boosting on cross-scheduled component carriers (CC).
    Type: Application
    Filed: March 17, 2011
    Publication date: March 15, 2012
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Vikram Chandrasekhar, Anthony Ekpenyong, Runhua Chen
  • Publication number: 20110243009
    Abstract: The primary serving base station transmits PDSCH with zero energy on the inter-cell CRS resource element location. This is called mute PDSCH. Within the first Physical Resource Block (PRB 0), the RE positions in the frequency domain are indexed between 0 and 11. The muted PDSCH RE positions per antenna port are computed using the cell IDs of all CoMP cells other than the cell ID i. The invention defines the Orthogonal Frequency Division Multiplexing (OFDM) symbols in which muting occurs.
    Type: Application
    Filed: March 30, 2011
    Publication date: October 6, 2011
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Vikram Chandrasekhar, Eko N. Onggosanusi, Anthony Ekpenyong, Runhua Chen
  • Publication number: 20100124930
    Abstract: A system and method are provided wherein one or more femtocell base stations are deployed within a range of a cellular base station and utilize substantially the same frequency band as the cellular base station. Each femtocell base station may be configured to employ one or more interference avoidance techniques such that coexistence between the cellular and the corresponding femtocell base station is enabled. The interference avoidance techniques employed may include use of randomized time or frequency hopping; randomly selecting a predetermined number, or identifying one or more unutilized, frequency subchannels for signal transmission; using two or more transmit and two or more receive antennas; nulling one or more transmissions in a direction of a nearby cellular base station user; handing off at least one cellular user to one of the femtocell base stations and vice versa; and/or reducing the transmission power of at least one femtocell base station.
    Type: Application
    Filed: November 19, 2009
    Publication date: May 20, 2010
    Inventors: Jeffrey G. Andrews, Vikram Chandrasekhar
  • Publication number: 20080080439
    Abstract: In an embodiment, a wireless communication system (100, FIG. 1) includes one or more nodes (102-108) and one or more user equipments (UE) (110). A node may apply (502, FIG. 5) a cell-specific spreading code to a cell identifier, which indicates an identity of a cell (113, FIG. 1) serviced by the node. The node may insert (504, FIG. 5), into a frame (200, FIG. 2), at least one synchronization channel symbol, which corresponds to the spread cell identifier, and the node may transmit (506, FIG. 5) the frame over an air interface. A UE may receive (702, FIG. 7) a frame from the air interface. The UE may despread (708) the spread cell identifier, and acquire (712) a cell identifier corresponding to a particular cell.
    Type: Application
    Filed: September 29, 2006
    Publication date: April 3, 2008
    Inventors: Ahsan U. Aziz, Vikram Chandrasekhar, James Wesley McCoy